Eur J Cardiothorac Surg 2001;20:335-338
© 2001 Elsevier Science NL
Improved pre-operative mediastinal staging in non-small-cell lung cancer by serial sectioning and immunohistochemical staining of lymph-node biopsies
J.Wolter A. Oosterhuisa,
Paul H.M.H. Theunissenb,
Ewald C.M. Bollena
a Department of Surgery, Atrium Medical Centre (Atrium Medisch Centrum), 6401 CX Heerlen, The Netherlands
b Department of Pathology, Atrium Medical Centre (Atrium Medisch Centrum), 6401 CX Heerlen, The Netherlands
Received 21 November 2000;
received in revised form 23 April 2001;
accepted 1 May 2001.
Corresponding author. Tel.: +31-384247058; fax: +31-384542040
e-mail: j.oosterhuis{at}tip.nl
 |
Abstract
|
|---|
Objective: Mediastinal staging of non-small-cell lung carcinoma (NSCLC) by mediastinoscopy suffers from a low sensitivity, leading to a number of patients with unforeseen N2 disease at thoracotomy. This study was undertaken to assess whether pre-operative staging could be improved by serial sectioning and immunohistochemical staining of mediastinoscopy biopsies. Methods: In 183 consecutive patients with NSCLC, a thoracotomy was performed after a thorough mediastinal staging by computed tomography scan and cervical mediastinoscopy. In 158 patients (88%), a mediastinal node dissection was performed, revealing unforeseen N2 disease in 24 cases (15%). The preserved mediastinoscopy biopsies of these patients were retrospectively serially sectioned and stained with MNF 116. Results: Metastases could be identified in seven cases (30%), reducing unforeseen N2 disease from 15 to 10%. The number of patients who could theoretically benefit from neo-adjuvant therapy would have been increased by at least 10%. Conclusions: Pre-operative mediastinal staging can be improved considerably by serial sectioning and immunohistochemical staining of mediastinoscopic biopsy specimens.
Key Words: Lung neoplasms • Lymphatic metastases • Mediastinum • Mediastinoscopy • Neoplasm staging • Immunohistochemistry
|
1. Introduction
|
|---|
Mediastinal lymphatic staging forms an important aspect of pre-operative work-up of patients with potentially resectable non-small-cell lung cancer (NSCLC). Patients may be selected for primary treatment by surgery in the absence of systemic or mediastinal metastases [1]. Pre-operative mediastinal staging is usually done by computed tomography (CT) scan and cervical mediastinoscopy. Since CT scan has been shown to suffer from low sensitivity and specificity to detect mediastinal metastases, cervical mediastinoscopy is mandatory to accurately stage patients before surgery [2,3]. Although mediastinoscopy has a specificity of 100%, its sensitivity to detect N2 or N3 disease is lower than 90%, as has been demonstrated in several studies [4,5]. Albertucci et al. [4] compared in a prospective study the results of mediastinoscopy in 160 patients with stages I–III NSCLC with mediastinal node dissection (MND) at thoracotomy and found unforeseen N2 disease in 21 of 140 patients (15%) with a negative mediastinoscopy. Using a policy of selective mediastinoscopy and performing a sampling of nodes at thoracotomy, with lymphadenectomy if frozen sections were positive, De Leyn et al. [5] found unforeseen N2 disease in 14.5% in a retrospective study of 859 patients with NSCLC. Although resectability of this so-called unforeseen N2 disease is as high as 95%, the reported 5-year survival rates are lower than for patients with stage I and II disease [6]. It has been demonstrated that the prognosis of patients with N2 disease may be improved by neo-adjuvant chemotherapy and for this reason accurate pre-operative staging is of utmost importance [7]. Methods to decrease the rate of unforeseen N2 disease should therefore be investigated. Despite promising reports, the use of magnetic resonance imaging (MRI) and positron emission tomography (PET) in pre-operative mediastinal staging have, as yet, not replaced surgical staging by mediastinoscopy [8].
In recent years, immunohistochemistry has been used in histopathology to improve post-operative lymphatic staging of several tumours [9]. Also in NSCLC occult, prognostically significant lymphatic metastasis has been detected after resection with immunohistochemistry [10–12]. Improving post-operative staging using immunohistochemistry may lead to stage migration, but will not alter patient management. In sentinel node techniques currently employed in breast cancer, malignant melanoma and other types of tumours, immunohistochemistry is used to improve detection of lymph-node metastasis before resectional therapy and to guide the oncologist in the choice of (neo-) adjuvant therapy [13]. These findings prompted us to investigate the possible use of immunohistochemistry in improving pre-operative mediastinal staging by mediastinoscopy. In the following study, we compare the mediastinoscopic lymph-node biopsies of patients who were diagnosed with unforeseen N2 disease after MND with staining by a routine technique and an immunohistochemical technique.
|
2. Material and methods
|
|---|
From January 1995 to December 1999, 258 consecutive patients were seen at the Atrium Medical Center, Heerlen, The Netherlands, with potentially resectable primary NSCLC, based on findings of at least chest radiographs, CT scan, bronchoscopy and pulmonary function analysis. After informed consent, 250 patients were staged by cervical mediastinoscopy and underwent a thoracotomy if N2 or N3 disease was excluded, as described elsewhere [14]. As a rule, at least three node stations (4L, 7, 4R) were sampled at mediastinoscopy. A cervical mediastinoscopy was only omitted in the pre-operative work-up in eight cases of severe silicosis or rare anatomical problems, e.g. distorted anatomy due to, for example, previous tracheotomy or severe cervical arthrosis. These eight patients were excluded from this study. Lymph-node biopsy specimens were routinely fixed in formalin, embedded in paraffin, sectioned at two levels and routinely stained with haematoxylin and eosin (H&E) for histological examination. In 67 (26%) cases, N2 or N3 disease was found at mediastinoscopy and these patients were subsequently excluded from this study. In all other 183 cases, a thoracotomy was done. At thoracotomy, the tumour was found to be irresectable in four cases, in all other cases a resection of the tumour was done. An ipsilateral mediastinal lymph-node dissection (MND) was always performed as part of the resection, as described elsewhere [14]. Resected lymph nodes were mapped by the surgeon according to international classification [15]. In 17 cases with macroscopically normal mediastinal lymph nodes, an MND was omitted because of substantial blood loss during the resection or a prolonged procedure. In a further four patients, resection had to be limited to a segmentectomy because of the patients restricted pulmonary reserve and in these cases MND was also omitted. Thus, in 158 patients (90%) an MND was performed at thoracotomy. Pathological examination of the lymph nodes obtained at thoracotomy was done in the same way as described for mediastinoscopy. In 25 cases (15%) N1 disease and in 24 cases (15%) N2 disease was found in the MND specimens. However, in four cases the only N2 station involved was unreachable by cervical mediastinoscopy (one patient at station 5, two patients at station 8 and one patient at station 9). In 20 cases (12%), at least one of the stations biopsied at mediastinoscopy was involved and the cervical mediastinoscopy result was truly false-negative. Details of these patients are given in Table 1.
The preserved mediastinoscopy biopsy specimens at the stations which were false-negative of these 20 patients were re-examined after serial sectioning and immunohistochemical staining. Formalin-fixed and paraffin-embedded tissue blocks were cut into 3 µm thick sections at nine levels at 100–150 µm intervals. The sections were incubated with an anti-keratin monoclonal antibody (clone MNF 116; DAKO a/s Denmark) after pre-treatment with pepsin (0.1% in 0.1 N HCl for 15 min at 37°C). The detection system of the immunohistochemical staining was based on an indirect streptavidin–biotin method. Antibody binding was visualised using DAB peroxidase substrate as chromogen. Sections were counterstained with haematoxylin. All sections were evaluated for the presence of immunoreactive cells that also showed morphological characteristics of tumour cells.
|
3. Results
|
|---|
The 20 patients (18 males, two females) had a median age of 69.6 years (range 56.5–76.8 years). An average of three node stations were biopsied per patient at mediastinoscopy. The primary tumour was located in the right or left lower lobe in 12 patients, in the right or left upper lobe in seven patients and in the middle lobe in one patient. At MND, metastasis was found at one station in 13 cases, at two stations in five cases, at three stations in one case and at four stations in another case. When comparing the MND results with the H&E stained cervical mediastinoscopy specimens, in two patients two stations were false-negative and in 18 patients one station was false-negative. When comparing the MND results with the immunohistochemically stained cervical mediastinoscopy specimens, the following was found. In seven cases immunohistochemistry showed micrometastasis in the mediastinoscopy biopsy specimens, consisting mostly of small cluster tumour cells in several sections. In two of these seven cases, the pathologist detected metastatic cells in the H&E sections retrospectively. In the other 13 cases, the immunohistochemically stained sections did not show any metastatic cells and concurred with the H&E stained sections.
|
4. Discussion
|
|---|
In the absence of systemic metastases, management and prognosis of NSCLC is determined by the presence or absence of mediastinal metastases [1]. The selection of patients for surgery should therefore be guided by an accurate a test as possible to detect mediastinal metastases pre-operatively. In the current retrospective study, mediastinoscopy was combined with serial sectioning and immunohistochemical staining to assess whether unforeseen N2 disease could be reduced. In 258 consecutive patients with potentially resectable NSCLC, N2 or N3 disease was diagnosed in 26% of cases after a thorough mediastinal staging by CT scan and cervical mediastinoscopy. In 24 patients (15%) in whom the tumour was resected, unforeseen N2 disease was encountered at MND. The rates of N2 disease detected by mediastinoscopy pre-operatively and unforeseen N2 disease at thoracotomy are in accordance with the literature [4,5,16]. With serial sectioning and immunohistochemical staining of the preserved mediastinoscopy specimens, we were able to identify retrospectively N2 disease in seven of 24 cases which were initially reported to be normal by H&E staining.
Cervical mediastinoscopy detects N2 and N3 disease with a specificity of 100% but has a relatively low sensitivity of less than 90% [3–5]. The reason for a low sensitivity may be found in several factors. Firstly, node stations 5, 6, 8 and 9 cannot be reached by standard cervical mediastinoscopy. This was the reason for unforeseen N2 disease in four of 24 patients in this series. Secondly, sampling errors can occur because often fragments of nodes are removed at mediastinoscopy, while the complete node station is removed at MND. This was the case in 13 of 24 patients with unforeseen N2 disease in this study. Thirdly, histopathological examination of biopsies is usually done in standard H&E stained material, in which case small numbers of metastatic cells can easily be overlooked. Lastly, if tissue is sectioned at a limited number of levels, small metastases may be missed. A combination of the last two factors accounted for unforeseen N2 disease in the seven patients in whom the immunohistochemical stained sections showed metastases retrospectively. Had these patients been diagnosed with N2 disease pre-operatively, this would have reduced the rate of unforeseen N2 disease by 30%. The total number of patients diagnosed as stage IIIA pre-operatively, in which cases neo-adjuvant therapy could be considered, would have increased by 10% from 67 to 74 patients. To be of practical significance, serial sectioning and immunohistochemical staining would have to be performed on all 158 patients with a negative mediastinoscopy to detect the seven false-negative biopsies, which is a yield of 4.4%. In this study, serial sections were done at nine levels, showing metastases at several levels in all cases. Probably, the same rate of detection of metastases could be reached with fewer sections.
We did not evaluate the biopsy specimens of patients with a true-negative mediastinoscopy by staining with anti-keratin antibodies. Although no N2 disease was found in the MND of these patients, it is possible that some of them had micrometastatic N2 disease, which was missed by the pathologist in H&E stained sections of the MND tissue. Whether this micrometastatic N2 disease could be detected by immunohistochemically stained mediastinoscopy biopsies is a matter for further research. Although micrometastatic N2 disease has been shown to have prognostic value, neo-adjuvant therapy could only be considered in these cases if it can be detected pre-operatively in a reliable manner [10,11]. Recent studies have compared non-surgical mediastinal staging by FDG–PET scanning with surgical staging by mediastinoscopy and mediastinal lymphadenectomy [17]. Although our technique has not been compared with a non-invasive staging technique like FDG–PET, both seem to have fewer false-negative results compared to conventional techniques [17]. To our knowledge, surgical staging by mediastinoscopy and immunohistochemical staining has not been compared with non-surgical staging. Theoretically, false-negative results of FDG–PET caused by micrometastatic disease, could be identified by immunohistochemical staining at mediastinoscopy.
Immunohistochemistry in lung cancer has previously been used to detect occult, prognostically relevant lymphatic metastases after oncological resections [10–12]. This study shows that the detection of lymph-node metastasis in NSCLC by immunohistochemistry in mediastinoscopy biopsy specimens is feasible and could lead to improved staging before surgical resection. The potential impact on patient management and prognosis needs further evaluation.
|
Footnotes
|
|---|
Presented at the 8th European Conference on General Thoracic Surgery of the European Society of Thoracic Surgeons, London, UK, November 1–4, 2000.
|
References
|
|---|
-
Mountain C.F. Revisions in the international system for staging lung cancer. Chest 1997;111:1710-1717.[Abstract/Free Full Text]
-
Bollen E.C., Goei R., 't Hof-Grootenboer B.E., Versteege C.W., Engelshove H.A., Lamers R.J. Interobserver variability and accuracy of computed tomographic assessment of nodal status in lung cancer. Ann Thorac Surg 1994;58:158-162.[Abstract]
-
Gdeedo A., Van Schil P., Corthouts B., Van Mieghem F., Van Meerbeeck J., Van Marck E. Prospective evaluation of computed tomography and mediastinoscopy in mediastinal lymph node staging. Eur Respir J 1997;10:1547-1551.[Abstract]
-
Albertucci M., DeMeester T.R., Golomb H.M., MacMahon H.K., Ryan J.W., Iascone C. Use and prognostic value of staging mediastinoscopy in non-small-cell lung cancer. Surgery 1987;102:652-659.[Medline]
-
De Leyn P., Vansteenkiste J., Cuypers P., Deneffe G., Van Raemdonck D., Coosemans W., Verschakelen J., Lerut T. Role of cervical mediastinoscopy in staging of non-small cell lung cancer without enlarged mediastinal lymph nodes on CT scan. Eur J Cardio-thorac Surg 1997;12:706-712.[Abstract]
-
De Leyn P., Schoonooghe P., Deneffe G., Van Raemdonck D., Coosemans W., Vansteenkiste J., Lerut T. Surgery for non-small cell lung cancer with unsuspected metastasis to ipsilateral mediastinal or subcarinal nodes (N2 disease). Eur J Cardio-thorac Surg 1996;10:649-654.[Abstract]
-
Martini N., Kris M.G., Flehinger B.J., Gralla R.J., Bains M.S., Burt M.E., Heelan R., McCormack P.M., Pisters K.M., Rigas J.R. Preoperative chemotherapy for stage IIIa (N2) lung cancer: the Sloan–Kettering experience with 136 patients. Ann Thorac Surg 1993;55:1365-1373.[Abstract]
-
Kernstine K.H., Stanford W., Mullan B.F., Rossi N.P., Thompson B.H., Bushnell D.L., McLaughlin K.A., Kern J.A. PET, CT, and MRI with Combidex for mediastinal staging in non-small cell lung carcinoma. Ann Thorac Surg 1999;68:1022-1028.[Abstract/Free Full Text]
-
Cote R.J., Peterson H.F., Chaiwun B., Gelber R.D., Goldhirsch A., Castiglione-Gertsch M., Gusterson B., Neville A.M. Role of immunohistochemical detection of lymph-node metastases in management of breast cancer. International Breast Cancer Study Group. Lancet 1999;354:896-900.[Medline]
-
Izbicki J.R., Passlick B., Hosch S.B., Kubuschock B., Schneider C., Busch C., Knoefel W.T., Thetter O., Pantel K. Mode of spread in the early phase of lymphatic metastasis in non-small-cell lung cancer: significance of nodal micrometastasis. J Thorac Cardiovasc Surg 1996;112:623-630.[Abstract/Free Full Text]
-
Dobashi K., Sugio K., Osaki T., Oka T., Yasumoto K. Micrometastatic P53-positive cells in the lymph nodes of non-small-cell lung cancer: prognostic significance. J Thorac Cardiovasc Surg 1997;114:339-346.[Abstract/Free Full Text]
-
Goldstein N.S., Mani A., Chmielewski G., Welsh R., Pursel S. Immunohistochemically detected micrometastases in peribronchial and mediastinal lymph nodes from patients with T1, N0, M0 pulmonary adenocarcinomas. Am J Surg Pathol 2000;24:274-279.[Medline]
-
Giuliano A.E., Dale P.S., Turner R.R., Morton D.L., Evans S.W., Krasne D.L. Improved axillary staging of breast cancer with sentinel lymphadenectomy. Ann Surg 1995;222:394-399.[Medline]
-
Bollen E.C., van Duin C.J., Theunissen P.H., Hof-Grootenboer B.E., Blijham G.H. Mediastinal lymph node dissection in resected lung cancer: morbidity and accuracy of staging. Ann Thorac Surg 1993;55:961-966.[Abstract]
-
Mountain C.F., Dresler C.M. Regional lymph node classification for lung cancer staging. Chest 1997;111:1718-1723.[Abstract/Free Full Text]
-
Graham A.N., Chan K.J., Pastorino U., Goldstraw P. Systematic nodal dissection in the intrathoracic staging of patients with non-small cell lung cancer. J Thorac Cardiovasc Surg 1999;117:246-251.[Abstract/Free Full Text]
-
Vansteenkiste J.F., Stroobants S.G., De Leyn P.R., Dupont P.J., Bogaert J., Maes A., Deneffe G.J., Nackaerts K.L., Verschakelen J.A., Lerut T.E., Mortelmans L.A., Demedts M.G. Lymph node staging in non-small-cell lung cancer with FDG–PET scan: a prospective study on 690 lymph node stations from 68 patients. J Clin Oncol 1998;16:2142-2149.[Abstract]
This article has been cited by other articles:
|
|
|
|
 
D. Lardinois, P. De Leyn, P. Van Schil, R. R. Porta, D. Waller, B. Passlick, M. Zielinski, K. Junker, E. A. Rendina, H.-B. Ris, et al.
ESTS guidelines for intraoperative lymph node staging in non-small cell lung cancer
Eur. J. Cardiothorac. Surg.,
November 1, 2006;
30(5):
787 - 792.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
X. T. Wang, W. Sienel, S. Eggeling, C. Ludwig, E. Stoelben, J. Mueller, C. A. Klein, and B. Passlick
Detection of disseminated tumor cells in mediastinoscopic lymph node biopsies and lymphadenectomy specimens of patients with NSCLC by quantitative RT-PCR
Eur. J. Cardiothorac. Surg.,
July 1, 2005;
28(1):
26 - 32.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
E. Cetinkaya, A. Turna, P. Yildiz, R. Dodurgali, M. A. Bedirhan, A. Gurses, and V. Yilmaz
Comparison of clinical and surgical-pathologic staging of the patients with non-small cell lung carcinoma
Eur. J. Cardiothorac. Surg.,
December 1, 2002;
22(6):
1000 - 1005.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
B. Passlick, B. Kubuschock, W. Sienel, O. Thetter, K. Pantel, and J.R. Izbicki
Mediastinal lymphadenectomy in non-small cell lung cancer: effectiveness in patients with or without nodal micrometastases -- results of a preliminary study
Eur. J. Cardiothorac. Surg.,
March 1, 2002;
21(3):
520 - 526.
[Abstract]
[Full Text]
[PDF]
|
|
|
Top
Abstract
1. Introduction
